ALS is a progressive disease affecting upper and lower motor neurons in the brain and the spinal cord, culminating in a death usually within 2-3 years after the onset of the symptoms.
Patients with ALS have no cure or treatment effective in improving clinical signs or parameters, although riluzole has been reported to prolong life without tracheostomy by 1-3 months in a subgroup of ALS. Other agents such as dextromethorphan, superoxide dismutase, vitamin E, ciliary neurotrophic factor have not yet convincingly shown their potency in improving the clinical symptoms or prolonging life in patients with ALS. Anecdotal or preliminary observations have also been made on the beneficial effects of cyclophosphamide and IGF-1 (insulin-like growth factor-1).
ALS patients generally show reduced amplitudes of muscle potentials after peripheral nerve stimulation (compound muscle action potentials or CMAPs). CMAPs can therefore be used as an objective measure of muscle power, and their decrease is related to the development of muscle weakness.